A Sudanese Christian woman remained under investigation by Khartoum police on Wednesday, her lawyer said, a day after she was stopped trying to leave Sudan following annulment of her apostasy death sentence.

Meriam Yahia Ibrahim Ishag, 26, is not under arrest but is being questioned at a police station over the authenticity of an emergency travel document issued by South Sudan, the lawyer Mohanad Mustafa told AFP.

Her American husband Daniel Wani and her two children, including a baby girl born while she was on death row, are with her.

“Nobody knows” how long the police investigation will take, Mustafa said, declining to say which country she was ultimately trying to reach after leaving Sudan.

Ishag was detained by national security agents at Khartoum airport while trying to leave Sudan on Tuesday afternoon, but was later taken to the police station.

In Washington, State Department spokeswoman Marie Harf downplayed the incident and said US officials would work with Khartoum to ensure the family would soon be on its way.

“They have not been arrested,” she added. “The government has assured us of their safety. The embassy has and will remain highly involved in working with the family and the government.”

A lower-court judge sentenced Ishag to death for apostasy on May 15, the case raising questions of religious freedom and sparking an outcry from Western governments and rights groups.

An appeal court freed her on Monday from the women’s prison where she had been detained with her children, but she immediately went into hiding because of death threats from Muslim extremists.

Born to a Muslim father and an Ethiopian Orthodox Christian mother, Ishag was convicted by the lower court under Islamic sharia law that has been in force in Sudan since 1983 and outlaws conversions on pain of death.

When Ishag was five her father abandoned the family, and she was raised according to her mother’s faith.

The Roman Catholic Archdiocese of Khartoum said she joined the Catholic church shortly before she married.